A Rewilded London: Reimagining a Wilder Future for the City

Rewilding means many things to many people. But what could it mean in an urban context? With the majority of the population living in towns and cities, and in the face of climate breakdown, re-evaluating how urban areas can support wildlife is more critical than ever. Rewilding urban spaces not only fosters biodiversity but also helps communities connect with nature, enhances well-being, and builds resilience against climate challenges.

Citizen Zoo will explore innovative approaches to urban rewilding. Learn about their groundbreaking species-focused projects, including beavers, water voles, and white storks, and how these efforts are transforming urban spaces into thriving wildlife habitats. Additionally, the presentation will delve into larger-scale initiatives embracing ecological processes, such as rewilding grazing programs and wetland creation, that are setting new standards for urban conservation.

Q&A with Elliot Newton

Elliot Newton is one of the co-founders of Citizen Zoo. With a background in urban wildlife conservation spanning well over 10 years, he has a breadth of experience in the development, design, and implementation of conservation projects in London. After establishing Citizen Zoo, he has overseen the delivery of the UK’s first rewilding conference in 2019, as well as the successful reintroduction of water voles to the Hogsmill and large marsh grasshoppers to various restored sites across Norfolk. His passion for beavers led to the creation of the London Beaver Working Group, which was a vessel for locating suitable reintroduction sites for the species across London. Elliot has been at the forefront of the Ealing Beaver Project, helping drive it forward from a dream to reality.

Are there any events coming up where I can learn more about rewilding?

The Biological Recording Company will be showcasing some rewilding projects in London in the Rewild London Virtual Symposium taking place on the 27th March 2024. This includes presentations about chalk grassland restoration, “renaturing” Hackney marshes and the River Crane Smarter Catchment initiative. Citizen Zoo is hosting a world-leading Rewilding Futures conference in Cambridge on 17-18th January 2025 in Cambridge. Over two days, the conference will bring together over 450 industry professionals, academics, landowners, NGOs, government bodies, and businesses to tackle pivotal issues in the field with unmissable presentations, expert panels, audience Q&As, networking opportunities and more. We only have around 25 tickets left so book now to avoid disappointment.

Where can I find out more about rewilding projects in London?

There are so many fantastic initiatives happening at the moment! I encourage you to visit the Citizen Zoo website to explore our current and upcoming projects. You might also consider attending the upcoming London Rewilding Symposium to learn more about urban rewilding efforts.

For further inspiration, do follow organisations such as the London Wildlife Trust, National Park City, Thames21, South East Rivers Trust, and The Conservation Volunteers. These groups are doing brilliant work to support conservation and rewilding across the region.

How are rewilding projects funded in London?

Projects are funded through a variety of sources, but one of the most impactful recent funding streams has been the GLA’s Rewild London Fund. This initiative has supported multiple rewilding projects across the capital, helping to drive forward vital conservation efforts.

What wildlife do you see in London in 20 years that is not here now?

I would love to see London fully embrace nature-based solutions to tackle climate change, with habitats seamlessly integrated into the city’s fabric. In 20 years, I envision free-living beaver populations thriving and being sustainably managed across London. The sight of white storks nesting within Greater London would also be truly incredible!

Further Info

More for environmental professionals

Check out our events on Eventbrite

Tiny Midges, Devastating Diseases

Some biting midges are able to transmit viruses that cause diseases in animals, particularly livestock. This talk will describe the ecology of these midges and how we can identify them. We will focus on the UK and northern Europe and explain how these areas are affected by the diseases carried by biting midges, and how these threats have increased in the last couple of decades.

Q&A with Dr Marion England

Dr Marion England is research fellow in Vector Ecology at The Pirbright Institute. Her research focuses on understanding the ecology of disease vectors, particularly biting midges, and how global change will impact arboviral threats. She leads the UK Culicoides Reference Laboratory which conducts surveillance of midges across the UK.

Does BTV infect any wild mammals found in the UK??

We assume deer in the UK are susceptible. We assume that they will become infected with BTV but we are not sure if they will be clinically affected. It may be that they will be totally fine and get over the virus in a short space of time, and we won’t see any disease. I’m more worried about epizootic haemorrhagic disease virus (EHDV) and what that could do to our deer. Potentially, however, our deer may be part of the BTV transmission cycle in the UK, so when deer populations are moving between farmed areas and woodlands, they could be helping to transmit the virus. The virus only affects ruminants so it’s very unlikely anything else would be affected.

What is the approximate cost of vaccine per animal?

In terms of the costs, it’s a few pounds per shot. It is a cost that farmers may struggle to meet depending on their herd/flock size.

The double doses are administered about four weeks apart. The vaccines are approved for use under emergency licence. The vaccines have not been in use for long enough to see how long immunity lasts, whether it’s six months, a year or longer. Its likely an annual booster will be required but we don’t have that information yet.

Do the midges have any predators?

These are native midges and birds and bats do eat them. However, they don’t make any real impact on midge populations because they are so numerous. In terms of biological controls, hitting them at the larval stage within the soil might be more effective. I am starting to look at the soil community that the midge larvae live in. They spend 90% of their life in the soil. Its understanding what other soil invertebrates might be predating them I think would be really interesting.

How many reproduction cycles does a female go through?

Probably two or three. The first time she takes a blood meal, she can acquire the virus and then lays an egg batch. As far as we know, the virus doesn’t transmit to the eggs/larvae. If females only went through this cycle once, we wouldn’t get any disease transmission. Based on this, we think two or three egg cycles but some will not survive that long.

Can transport of midges on aeroplanes explain outbreaks in new areas that can’t be explained by wind translocation?

BTV has popped up in the Netherlands twice in an area very close to Schiphol Airport, a massive international hub. The Netherlands is also a massive international shipping hub. A lot of products come into the Netherlands from across the world and then get dispatched across Europe. So midges can be on aeroplanes, however, there are questions around the cut-flower industry. Cut flowers are grown in places like Kenya, where BTV is endemic. If midges are resting in those cut flowers or on soils in pot plants, they could be transported to Europe in a chilled humid environment. In these cooler environments, their development slows down – they may go into a sort of stasis. When they arrive at their destination, if conditions are suitable they may survive and disperse.

Literature References

  1. Nelson et al (2022) A Qualitative Risk Assessment for Bluetongue Disease and African Horse Sickness: The Risk of Entry and Exposure at a UK Zoo: https://www.mdpi.com/1999-4915/14/3/502
  2. Holwerda et al (2024) Emergence of Bluetongue Virus Serotype 3, the Netherlands, September 2023: https://pmc.ncbi.nlm.nih.gov/articles/PMC11286052/
  3. Boender et al (2024) Spatial Transmission Characteristics of the Bluetongue Virus Serotype 3 Epidemic in The Netherlands, 2023: https://www.mdpi.com/1999-4915/16/4/625

Further Info

entoLIVE

entoLIVE webinars feature guest invertebrate researchers delving into their own invertebrate research. All events are free to attend and are suitable for adults of all abilities – a passion for invertebrates is all that’s required!

entoLIVE is delivered by the Biological Recording Company in partnership with the British Entomological & Natural History Society, Royal Entomological Society and Amateur Entomologists’ Society, with support from Buglife, Field Studies Council and National Biodiversity Network Trust.

Check out more invertebrate research, publications and events from the entoLIVE partner websites:

More on invertebrates

Check out upcoming events on Eventbrite

Plants for Pollinators: Using DNA to Explore Relationships in Gardens

Many “plants for pollinators” recommendation lists exist; however they often rely on anecdotal evidence, show inconsistencies between lists, and cater to a limited range of pollinators. To effectively support pollinators in gardens throughout the year, a deeper understanding of foraging behaviour is crucial. In this talk, Dr Abigail Lowe takes us through her PhD research, which used DNA techniques to identify pollen collected by hoverflies, bumblebees, honeybees and solitary bees. Explore the similarities and differences in foraging behaviour within each group, and observe whether these patterns changed over two years. Discover whether native or non-native plants were preferred, and gain insights into how we can improve our gardens to provide support for these important insects.

Q&A with Dr Abigail Lowe

Dr Abigail Lowe is an Interdisciplinary Ecologist within the Biological Records Centre at the UK Centre for Ecology and Hydrology. Her research uses citizen science to understand the interaction of people, nature, and environmental data.

Is there one plant that you would recommend planting for pollinators?

I really don’t think there is one plant! However, one plant that gardeners don’t want to hear about and IS really important is bramble. Bramble often comes up in research as being great for pollinators, but obviously not a lot of people want their gardens to be full of bramble. The most important thing is making sure that you have plants in your garden from the beginning of the season right to the end. If you live in a warmer area, such as southern England, you want to make sure there is something in your garden in winter like Mahonia for bumblebees that are active through winter. Generally, make sure there’s a diversity of plants in your garden with different shapes and colours.

What percentage or proportion of pollinators are actually bees compared to all the other pollinators? 

There are about 280 species of bees in the UK and 6,000 species of pollinating insects, so the proportion of pollinators that are bees is not as large as many people would imagine based on how pollinators and bees are often synonymous in the media. However, not all pollinating insects are equal in terms of their ability to pollinate. How effective a pollinator is will depend on lots of factors, and will vary depending on the plant species being pollinated.

What is a near native plant?

With DNA, we can’t always get to species, so if we have a genus that appears in the DNA results that includes native and horticultural species, we classify it as near native – for example Quercus (oak) species can be native or non-native. Horticultural plants are genera or species that are very obviously introduced.

How do you know that your research is detecting species diversity rather than pollen abundance levels?

That’s a really good point and the technique is not perfect and has biological limitations. You’re right in that a pollinator could visit a plant and be completely covered in the one particular pollen. It is something that we acknowledge might be the case but we hope that by sampling lots of individuals throughout the year and at different times of the day, it does reduce that impact a little bit. The research shows that the same plants come up time and time again, no matter the method used, plus the meta barcoding approach that we used is found to be semi-quantitat­ive, so we assume that the abundance of pollen in the DNA is related to the actual abundance on the bodies of insects.

We do acknowledge that we don’t know how long the pollen has been on the insect’s body. We don’t know what sort of record that is – is it from the last hour, is it for a few hours? Bees will take their pollen back to feed their young and hoverflies will routinely clean themselves, so that’s another question really. The ultimate answer to any of these questions is that the more that you research, there are more questions to be asked.

What is the big research question that you think has come out in the work that you’ve done?

This might be a cop out answer, but the contribution to knowledge on individual specialisation. Not a lot of people are looking at individual specialisation and this research has bigger impacts. For instance, if insects are specialised, they are more likely to be vulnerable to environmental change, so there are big network theory questions around that. When we use observational methods to look at which plants are being used by pollinators, it’s actually quite hard to track an individual bumblebee around the landscape, whereas DNA meta barcoding can get you that broader spatial and temporal resolution which is what enabled the individual specialisation research.

Literature References

  1. Lowe et al (2022): Using DNA Metabarcoding to Identify Floral Visitation by Pollinators: https://www.mdpi.com/1424-2818/14/4/236
  2. Lowe et al (2022) Seasonal progression and differences in major floral resource use by bees and hoverflies in a diverse horticultural and agricultural landscape revealed by DNA metabarcoding: https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2664.14144
  3. Lowe et al (2022) Temporal change in floral availability leads to periods of resource limitation and affects diet specificity in a generalist pollinator: https://onlinelibrary.wiley.com/doi/full/10.1111/mec.16719
  4. Powney et al (2019) Widespread losses of pollinating insects in Britain: https://www.nature.com/articles/s41467-019-08974-9

Further Info

entoLIVE

entoLIVE webinars feature guest invertebrate researchers delving into their own invertebrate research. All events are free to attend and are suitable for adults of all abilities – a passion for invertebrates is all that’s required!

entoLIVE is delivered by the Biological Recording Company in partnership with the British Entomological & Natural History Society, Royal Entomological Society and Amateur Entomologists’ Society, with support from Buglife, Field Studies Council and National Biodiversity Network Trust.

Check out more invertebrate research, publications and events from the entoLIVE partner websites:

More on citizen science

Check out upcoming events on Eventbrite

Of Mice and Beavers: Rewilding Ealing One Rodent at a Time

Dr Sean McCormack discusses his work with Ealing Wildlife Group and their ‘Rewilding Ealing’ initiative, focusing on the successful reintroduction of Britain’s smallest and largest native rodent species, the Harvest Mouse and Eurasian Beaver. He also touches on some of the group’s wider conservation efforts and future plans.

These projects harness the local community and are all volunteer-led. The Ealing Beaver Project is a collaboration between Ealing Wildlife Group, Citizen Zoo, Friends of Horsenden and Ealing Council. It is the first truly urban London beaver reintroduction and is fully accessible to the public to enter freely and immerse themselves in a beaver-shaped landscape. A family of five beavers were reintroduced here to Paradise Fields in October 2023 with support from the Mayor of London and Beaver Trust, for whom Sean is an ambassador.

Q&A with Dr Sean McCormack

Dr Sean McCormack is a conservationist, vet and occasional TV and radio presenter who has always had a passion for the natural world. In 2016 he set up Ealing Wildlife Group, a community conservation group working in partnership with the local Council and other landowners on various species-focused projects including Barn Owls, Peregrine Falcons, Great Crested Newts, Bats, Swifts, Hedgehogs and more recently reintroducing both Britain’s smallest and largest native rodents to Ealing, the Harvest Mouse and the Eurasian Beaver.

What are the predator risks to harvest mice that concern you?

The harvest mice (Micromys minutus) are not wrapped in cotton wool and we see them as part of the ecosystem, being an important part of the food chain with natural predators and one of the project aims is to put back that missing cog. We are concerned about unnatural predation of the mice causing local extinction of the reintroduced populations. We are particularly concerned about cats as they hunt for entertainment and even a single cat can cause a lot of damage if it is catching several prey items per day. The density of cats in the urban landscape makes this a particular issue. One of our sites identified for release was not used due to the fact that it was surrounded by residential areas and we felt the risk from cat predation was too high. We’ve also heard from some dog owners walking their dogs on Horsenden Hill that their dogs love to run off and catch mice so we’ve been trying to educate them that this could be damaging populations of a rare species and the response has been generally positive.

Have you had any beavers escape?

No! To reduce the temptation for the beavers (Castor fiber) to want to escape, we’ve given them a huge amount of space. The recommendation form the Beaver Trust was two hectares of good quality habitat for a family of beavers and we’ve created an enclosure with 8 hectares, particularly as we know there is a fair amount of human activity on site and we wanted the beavers to easily be able to get away from us! The pressure for a beaver to want to escape tends to happen when you get more and more beavers in a territory. The oldest offspring will then start wanting to disperse to find their own territory and start their own family. To mitigate this, the oldest offspring should be removed when the family gets too big for the enclosure. The fencing for the enclosure is a specially designed “beaver-proof” fence that has a skirt on the ground to prevent animals from digging out of the enclosure and an overhang to prevent animals from climbing over the fence. Any culverts and grates where water is coming in or out of the site have also been “beaver-proofed” where needed. We have had a team of wonderful volunteers who have been responsible for checking the fencing on a daily basis for the first year, and now check it 3-4 times per week. We have a plan for if the beavers escape and I’m confident that we could recover them quickly.

Do you expect to let the Paradise Beavers go free, either naturally or deliberately?

These beavers are at this site under a licence so it is not possible to let them naturally disperse into the surrounding area. Release of these beavers into the wild would need to be planned. Our licence is for 5 years. Natural England may suggest that the licence is continued but we need to consider the amount of work and effort that goes into maintaining this population and, as the licence holder, I can’t commit to looking after a family of beavers for the rest of my life. The aim of this project was never to restore beavers to Greater London at a population level, it is more of a demonstration and engagement project to see how we can live alongside one family of beavers. Paradise Fields would not be the best place to release beavers from as it has a busy road on one boundary and a very urban landscape (a retail park) on another. We’re in a strange situation politically at this current point in time where beavers are classed as a native protected species but the only way that they can be released is behind an expensive fence. There are signs that this may change with the new government, and I hope to see the kits born this year to be released at a suitable wetland environment site within Greater London without an enclosure!

Are you seeing an increase in the wider biodiversity from the beaver project?

Building up robust and statistically significant data to evidence this takes time, so we’re not quite there yet with evidencing this scientifically. However, we are definitely starting to see positive changes. We’re seeing more bats and new bat species on site, which are a good indicator for insect populations. We can see on a macro level that the number of invertebrates within the water is much improved, and we’ve recorded new species of Gammarus (freshwater shrimp), cased caddisflies. We’ve seen water rail (Rallus aquaticus) and snipe (Gallinago gallinago) on site for the first time. Remember we are only one year in and I can’t wait to see how transformed the site is by the end of the project.

Further Info

More for environmental professionals

Check out our events on Eventbrite

The Wilder Sensing Guide to Mastering Bioacoustic Bird Surveys

Learn how to effectively plan and conduct bird surveys using bioacoustic methods, utilising sound recorders and cutting-edge AI tools for data analysis and interpretation.

Bioacoustics is revolutionising bird monitoring, offering a non-invasive method to record bird activity continuously, even over extended periods, and generating valuable species occurrence, richness and distribution data.

In this blog, you’ll learn how bioacoustics can reveal critical insights, such as tracking when species arrive at and depart from a site, as well as behavioural patterns through different call types. The presentations will provide practical guidance on setting up sound recorders, tailoring your survey design based on the size of your site and survey objectives, and harnessing the power of AI to process and analyse large volumes of sound data.

Key topics include:

  • Setting up and managing passive audio recorders for bioacoustics surveys
  • Designing surveys that fit your needs, budget and site characteristics
  • Interpreting AI-processed sound data to uncover species behaviour, distribution and richness

Bioacoustics Recorders 101

Paul Howden-Leach (Wildlife Acoustics)

Bioacoustics recorders are a cost-effective and reliable solution for the periodic, seasonal, or ongoing long-term acoustic monitoring of birds and other wildlife in any field conditions. Understanding how the device settings and the best place to position it can make all the difference to what wildlife is captured, and what is missed. In this presentation, Wildlife Acoustics share some of their top tips for getting the most out of your recorder.

Designing Bioacoustics Surveys

Geoff Carss (Wilder Sensing)

Designing a bioacoustics survey involves several key considerations, including defining your monitoring objectives, understanding the habitat types or changes you aim to study, selecting appropriate control locations, and addressing practical factors like site access and health and safety. This presentation delves into these aspects, providing guidance to help you create an effective survey tailored to your needs.

Understanding and Interpreting Your Bioacoustics Data

Cat Scutts (Wilder Sensing)

Bioacoustic surveys can produce millions of species-level records during long-term monitoring, offering opportunities to explore new questions and gain deeper insights into biodiversity. But how do you design an effective survey? How does this align with traditional survey methods? What stories is the data telling us about the biodiversity recorded on site? This presentation and demo demonstrate strategies for designing surveys and interpreting bioacoustic data to maximise its potential.

Useful links

What evidence base have you used to set detection confidence at 0.85 and location probability at 0.1?

Cat: At the moment there isn’t an evidence base. It’s through use and inspection that we’ve come to those levels. What species or metric you’re looking at will really influence the settings you use. For instance, if you want a really solid baseline that you don’t have to go away and validate, then put the confidence up very high (i.e. 0.9 or 0.95). That will likely remove species that are present too, but it’s a balance between your time and the resources that you have [available for validation].

The location probability is based on eBird data. We are looking at refining and changing it so that it doesn’t cut out so many of the under-reported species. Again, 0.1 is a rule of thumb for what seemed to make the most sense when looking through species lists. Looking at your species list is a really good starting point to asking validation questions. Are these the species that you’d expect to see at this location? Does this match with any seasonal surveys previously undertaken? Are there any unexpected species?

Geoff: We‘ve started thinking about species-specific thresholding, to try to get the balance a bit more. For example, some birds vocalise more than others and they have different ranges. This gets into some quite serious research [which is] outside of the scope of our work at Wilder Sensing. [But] there are PhD students and post docs looking at this. When evidenced we can adopt [the results of] some of this research and bring it into the platform.

Can bioacoustics data be linked to functional diversity of sites?

Functional diversity is the diversity of [species fulfilling] different ecological functions on sites, i.e., different traits and different roles in the ecosystem.

Cat: Our tool allows you to look at assemblages from your species list and [investigate] what [the community] tells you about the habitat and the site. If you have different sets of species [present] that represent those different niches and habitat types, [you can infer results related to functional diversity]. What I didn’t show in my presentation is that when you choose individual species to view them in the dashboard, you can choose more than one. If you’ve got a set of ground feeders, or wading birds [for example] that you want to look at, you can [select and view them] together [to investigate the results]; and maybe contrast with other functionalities as well.

Geoff: Work by Ecosulis and CreditNature is probably more advanced in relation to this than what we’re doing at Wilder Sensing. Our focus is [on facilitating] monitoring species assemblages over time. Based on research that I’ve looked at, the bird assemblage is more sensitive as an indicator of change than the plant assemblage.

Is the Wilder Sensing subscription package flexible?

Geoff: Absolutely. We recognise that people have very different requirements, from doing annual or multi-year surveys through to a two- or three-week survey, and we support all of these different use cases. Just contact us via info@wildersensing.com or our website contact form and we can have a discussion on what’s right for you.

Is there a good method for using bioacoustics for wider baseline monitoring such as assessing a habitat creation scheme?

Geoff: We’ve only been doing this 2-2.5 years, so we’ve only got a limited amount of data to date. I think there’s a really good argument for creating habitat indices, to help us understand aspects such as how habitat changes over time as it moves from grassland to scrub, how a site is developing over that time, and how it compares to other sites. Is your assemblage changing in line with other interventions that might be similar? What can you identify as ‘good’ practice – ‘good’ is a very loaded word in that context – so what’s a better practice than others, if you’re trying to achieve an outcome of species richness or target species recovery, etc?

For long-term surveys of 30+ years, then there are a few factors to consider. One is making sure your recordings are really good quality because in 20 to 30 years’ time, who knows how technology will have advanced? Make sure your recordings are well backed up and protected. Anyone using our platform will have their recordings archived into deep storage so we don’t lose them. Then in five to ten years, [when] there are better models and algorithms, we can go back and reprocess all [of] that data [if requested]. Control as many of the variables as you can: use the same recorders over a long period of time and make sure they are maintained. You’re trying to remove the variability from the recorders themselves. That can be really important.

Cat: Looking at the overall scope and scale of your survey will inform the resolution that you need to sample at. You might want to survey on a rotation, depending on the overall length of your project and the size of your site. For example, surveying every 5 years if your [project] period is 30-40 years. If it’s a ten-year project over a really vast area, then you might move those recorders on a two- or three-yearly basis. It will depend on your resources and the number of recorders that you have available, as well as the number of people you have to sort out battery and SD card [changes]. So, looking at the overall scope and scale [of your project will indicate] the kind of resolution that you want to be sampling.

Is there a list of species that can’t be differentiated, such as the hawfinch and robin?

Geoff: There are, and it’s not just birds. I’ve heard a recording of a Mole Cricket that I could have sworn was a Nightjar!

We are building up a list of confusion species and working on fixing these issues. For example, we started picking a lot of Short-toed Tree Creepers. Tree creepers are not the easiest to spot at the best of times, are very rare and I’ve never found one when ringing. One of the volunteers then suggested that the confusion was with a Dunnock!

The tool [analyses for detections in] three second sound clips so we can also look at the pattern that is being registered. For example, if we’ve picked up a single Hawfinch call, and we look at the species detection tags registered before and after the call we can make assumptions based on this. If the data states ‘Robin, Robin, Robin, Robin, Robin, Hawfinch, Robin, Robin, Robin, Robin, Robin’, it is most likely that the Hawfinch-tagged call is actually a Robin.

We are looking at ways of solving these issues, but it should be noted that not all fixes will come from machine learning.

Wilder Sensing ecoTECH blogs

  1. How Can We Use Sound to Measure Biodiversity: https://biologicalrecording.co.uk/2024/07/09/bioacoustics-1/
  2. Can Passive Acoustic Monitoring of Birds Replace Site Surveys blog: https://biologicalrecording.co.uk/2024/09/17/bioacoustics-2/
  3. The Wilder Sensing Guide to Mastering Bioacoustic Bird Surveys: https://biologicalrecording.co.uk/2024/11/26/bioacoustics-3/
  4. Bioacoustics for Regenerative Agriculture: https://biologicalrecording.co.uk/2025/03/31/bioacoustics-for-regen-ag/
  5. AI-powered Bioacoustics with BirdNET: https://biologicalrecording.co.uk/2025/07/08/birdnet/

Event partners

This blog was produced by the Biological Recording Company in partnership with Wilder Sensing, Wildlife Acoustics and NHBS.

More for environmental professionals

Check out our events on Eventbrite